Many diseases are associated with the changes that occur in the nuclei of cells. In particular, some types of cancers are associated with the presence of additional genetic material in cells. For example, a certain type of breast cancer is associated with an over abundance (e.g., over expression) of the human epidermal growth factor 2 (“HER2”) versus the number of chromosome 17s found in the cell. By detecting the number of HER2 genes versus the number of chromosome 17s in a tissue sample, this particular type of breast cancer can be more readily identified and treatment options can be evaluated.
In a conventional tissue analyzing system, a pathologist uses a microscope to view a tissue sample that has been stained with a “cocktail” mix that includes special gene markers that attach themselves to particular genes, chromosomes or portions thereof. The markers make the attached chromosomes or genes appear as differently colored regions on the stained slide. The pathologist can count or estimate how many objects truly represent the marked genetic material versus extraneous junk in the slide and then make a determination whether a gene is amplified in a particular tissue sample.